| Message ID | 1504613972-15847-1-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | util/qemu-thread-posix.c: Replace OS ifdefs with CONFIG_HAVE_SEM_TIMEDWAIT | expand |
On 05.09.2017 14:19, Peter Maydell wrote: > In qemu-thread-posix.c we have two implementations of the > various qemu_sem_* functions, one of which uses native POSIX > sem_* and the other of which emulates them with pthread conditions. > This is necessary because not all our host OSes support > sem_timedwait(). > > Instead of a hard-coded list of OSes which don't implement > sem_timedwait(), which gets out of date, make configure > test for the presence of the function and set a new > CONFIG_HAVE_SEM_TIMEDWAIT appropriately. > > In particular, newer NetBSDs have sem_timedwait(), so this > commit will switch them over to using it. OSX still does > not have an implementation. > The NetBSD part looks fine. It builds fine on NetBSD/amd64 8.99.2. All tests pass (with disabled PaX MPROTECT). > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Kamil Rytarowski <n54@gmx.com> > --- > It would be nice to gradually reduce the number of places > we do per-OS ifdeffery in favour of checking for the specific > feature we care about in each case... > Tested on Linux, NetBSD, OSX. > > configure | 15 +++++++++++++++ > include/qemu/thread-posix.h | 2 +- > util/qemu-thread-posix.c | 10 +++++----- > 3 files changed, 21 insertions(+), 6 deletions(-) > > diff --git a/configure b/configure > index fb7e34a..aa8d4d9 100755 > --- a/configure > +++ b/configure > @@ -4448,6 +4448,18 @@ if compile_prog "" "" ; then > fi > > ########################################## > +# check if we have sem_timedwait > + > +sem_timedwait=no > +cat > $TMPC << EOF > +#include <semaphore.h> > +int main(void) { return sem_timedwait(0, 0); } > +EOF > +if compile_prog "" "" ; then > + sem_timedwait=yes > +fi > + > +########################################## > # check if trace backend exists > > $python "$source_path/scripts/tracetool.py" "--backends=$trace_backends" --check-backends > /dev/null 2> /dev/null > @@ -5680,6 +5692,9 @@ fi > if test "$inotify1" = "yes" ; then > echo "CONFIG_INOTIFY1=y" >> $config_host_mak > fi > +if test "$sem_timedwait" = "yes" ; then > + echo "CONFIG_SEM_TIMEDWAIT=y" >> $config_host_mak > +fi > if test "$byteswap_h" = "yes" ; then > echo "CONFIG_BYTESWAP_H=y" >> $config_host_mak > fi > diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h > index e5e3a0f..f4296d3 100644 > --- a/include/qemu/thread-posix.h > +++ b/include/qemu/thread-posix.h > @@ -21,7 +21,7 @@ struct QemuCond { > }; > > struct QemuSemaphore { > -#if defined(__APPLE__) || defined(__NetBSD__) > +#ifndef CONFIG_SEM_TIMEDWAIT > pthread_mutex_t lock; > pthread_cond_t cond; > unsigned int count; > diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c > index 4e95d27..7306475 100644 > --- a/util/qemu-thread-posix.c > +++ b/util/qemu-thread-posix.c > @@ -168,7 +168,7 @@ void qemu_sem_init(QemuSemaphore *sem, int init) > { > int rc; > > -#if defined(__APPLE__) || defined(__NetBSD__) > +#ifndef CONFIG_SEM_TIMEDWAIT > rc = pthread_mutex_init(&sem->lock, NULL); > if (rc != 0) { > error_exit(rc, __func__); > @@ -196,7 +196,7 @@ void qemu_sem_destroy(QemuSemaphore *sem) > > assert(sem->initialized); > sem->initialized = false; > -#if defined(__APPLE__) || defined(__NetBSD__) > +#ifndef CONFIG_SEM_TIMEDWAIT > rc = pthread_cond_destroy(&sem->cond); > if (rc < 0) { > error_exit(rc, __func__); > @@ -218,7 +218,7 @@ void qemu_sem_post(QemuSemaphore *sem) > int rc; > > assert(sem->initialized); > -#if defined(__APPLE__) || defined(__NetBSD__) > +#ifndef CONFIG_SEM_TIMEDWAIT > pthread_mutex_lock(&sem->lock); > if (sem->count == UINT_MAX) { > rc = EINVAL; > @@ -256,7 +256,7 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms) > struct timespec ts; > > assert(sem->initialized); > -#if defined(__APPLE__) || defined(__NetBSD__) > +#ifndef CONFIG_SEM_TIMEDWAIT > rc = 0; > compute_abs_deadline(&ts, ms); > pthread_mutex_lock(&sem->lock); > @@ -304,7 +304,7 @@ void qemu_sem_wait(QemuSemaphore *sem) > int rc; > > assert(sem->initialized); > -#if defined(__APPLE__) || defined(__NetBSD__) > +#ifndef CONFIG_SEM_TIMEDWAIT > pthread_mutex_lock(&sem->lock); > while (sem->count == 0) { > rc = pthread_cond_wait(&sem->cond, &sem->lock); >
On 09/05/2017 07:19 AM, Peter Maydell wrote: > In qemu-thread-posix.c we have two implementations of the > various qemu_sem_* functions, one of which uses native POSIX > sem_* and the other of which emulates them with pthread conditions. > This is necessary because not all our host OSes support > sem_timedwait(). > > Instead of a hard-coded list of OSes which don't implement > sem_timedwait(), which gets out of date, make configure > test for the presence of the function and set a new > CONFIG_HAVE_SEM_TIMEDWAIT appropriately. > > In particular, newer NetBSDs have sem_timedwait(), so this > commit will switch them over to using it. OSX still does > not have an implementation. > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > It would be nice to gradually reduce the number of places > we do per-OS ifdeffery in favour of checking for the specific > feature we care about in each case... Yes, that's always been autoconf's philosophy: feature tests trump platform tests every time, because platforms can add features over time, and because an ifdef on a single feature test is easier to read than a list of platform names. > Tested on Linux, NetBSD, OSX. > Reviewed-by: Eric Blake <eblake@redhat.com> -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
diff --git a/configure b/configure index fb7e34a..aa8d4d9 100755 --- a/configure +++ b/configure @@ -4448,6 +4448,18 @@ if compile_prog "" "" ; then fi ########################################## +# check if we have sem_timedwait + +sem_timedwait=no +cat > $TMPC << EOF +#include <semaphore.h> +int main(void) { return sem_timedwait(0, 0); } +EOF +if compile_prog "" "" ; then + sem_timedwait=yes +fi + +########################################## # check if trace backend exists $python "$source_path/scripts/tracetool.py" "--backends=$trace_backends" --check-backends > /dev/null 2> /dev/null @@ -5680,6 +5692,9 @@ fi if test "$inotify1" = "yes" ; then echo "CONFIG_INOTIFY1=y" >> $config_host_mak fi +if test "$sem_timedwait" = "yes" ; then + echo "CONFIG_SEM_TIMEDWAIT=y" >> $config_host_mak +fi if test "$byteswap_h" = "yes" ; then echo "CONFIG_BYTESWAP_H=y" >> $config_host_mak fi diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h index e5e3a0f..f4296d3 100644 --- a/include/qemu/thread-posix.h +++ b/include/qemu/thread-posix.h @@ -21,7 +21,7 @@ struct QemuCond { }; struct QemuSemaphore { -#if defined(__APPLE__) || defined(__NetBSD__) +#ifndef CONFIG_SEM_TIMEDWAIT pthread_mutex_t lock; pthread_cond_t cond; unsigned int count; diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c index 4e95d27..7306475 100644 --- a/util/qemu-thread-posix.c +++ b/util/qemu-thread-posix.c @@ -168,7 +168,7 @@ void qemu_sem_init(QemuSemaphore *sem, int init) { int rc; -#if defined(__APPLE__) || defined(__NetBSD__) +#ifndef CONFIG_SEM_TIMEDWAIT rc = pthread_mutex_init(&sem->lock, NULL); if (rc != 0) { error_exit(rc, __func__); @@ -196,7 +196,7 @@ void qemu_sem_destroy(QemuSemaphore *sem) assert(sem->initialized); sem->initialized = false; -#if defined(__APPLE__) || defined(__NetBSD__) +#ifndef CONFIG_SEM_TIMEDWAIT rc = pthread_cond_destroy(&sem->cond); if (rc < 0) { error_exit(rc, __func__); @@ -218,7 +218,7 @@ void qemu_sem_post(QemuSemaphore *sem) int rc; assert(sem->initialized); -#if defined(__APPLE__) || defined(__NetBSD__) +#ifndef CONFIG_SEM_TIMEDWAIT pthread_mutex_lock(&sem->lock); if (sem->count == UINT_MAX) { rc = EINVAL; @@ -256,7 +256,7 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms) struct timespec ts; assert(sem->initialized); -#if defined(__APPLE__) || defined(__NetBSD__) +#ifndef CONFIG_SEM_TIMEDWAIT rc = 0; compute_abs_deadline(&ts, ms); pthread_mutex_lock(&sem->lock); @@ -304,7 +304,7 @@ void qemu_sem_wait(QemuSemaphore *sem) int rc; assert(sem->initialized); -#if defined(__APPLE__) || defined(__NetBSD__) +#ifndef CONFIG_SEM_TIMEDWAIT pthread_mutex_lock(&sem->lock); while (sem->count == 0) { rc = pthread_cond_wait(&sem->cond, &sem->lock);
In qemu-thread-posix.c we have two implementations of the various qemu_sem_* functions, one of which uses native POSIX sem_* and the other of which emulates them with pthread conditions. This is necessary because not all our host OSes support sem_timedwait(). Instead of a hard-coded list of OSes which don't implement sem_timedwait(), which gets out of date, make configure test for the presence of the function and set a new CONFIG_HAVE_SEM_TIMEDWAIT appropriately. In particular, newer NetBSDs have sem_timedwait(), so this commit will switch them over to using it. OSX still does not have an implementation. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- It would be nice to gradually reduce the number of places we do per-OS ifdeffery in favour of checking for the specific feature we care about in each case... Tested on Linux, NetBSD, OSX. configure | 15 +++++++++++++++ include/qemu/thread-posix.h | 2 +- util/qemu-thread-posix.c | 10 +++++----- 3 files changed, 21 insertions(+), 6 deletions(-) -- 2.7.4